Functional Resolution:
The Functional Resolution is the frequency at which the SFR amplitude equals the Discernment Limit (typically 10{87544f4b958fce1c89be16ae80d8737220922657377564151bb9b966540e4285}). Detail in an image that has a higher frequency than this “limiting frequency” is not easily distinguished by the average human observer.
Measurement Details:
The Functional Resolution is computed using these steps:
- Calculate the horizontal and vertical SFR curves
- Determine where the SFR amplitude for the Visual curve equals the Discernment Limit.
- Compute the average of the horizontal and vertical frequencies.
Examples:
The unacceptable functional resolution image has equal sensor resolution (50 dpi) as the acceptable image but much lower optical efficiency (50{87544f4b958fce1c89be16ae80d8737220922657377564151bb9b966540e4285}). The resulting functional frequency (27 dpi) is below specification (35 dpi).
Specifications:
Both the discernment limit and minimum functional resolution are required to specify functional resolution. These are accessible in the Functional Resolution tab. A conversion tool is available to calculate resolution units from dpi.
